Drum-type washing machine

ABSTRACT

The water circulation system of a drum-type washing machine uses one motor to drive both the circulation and drain pumps. The drum-type washing machine includes a motor having a shaft, the motor enabling forward and reverse rotation of the shaft; a circulation pump, installed on the shaft of the motor, for circulating water by a rotational operation of the motor, the circulating pump moving a first fluid from a water circulation inlet to a water circulation outlet by a centrifugal force; and a drain pump, installed on the shaft of the motor, for draining water by a rotational operation of the motor, the drain pump moving a second fluid from a drain inlet to a drain outlet by a frictional force.

[0001] This application claims the benefit of Korean Application No. 10-2002-0078812 filed on Dec. 11, 2002, which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a drum-type washing machine, and more particularly, to a drum-type washing machine having a water circulation system in which one motor is used to drive both the circulation and drain pumps.

[0004] 2. Discussion of the Related Art

[0005] Washing machines generally categorized into a pulsator type for washing laundry using a whirling water current and a drum type for washing laundry using a falling of the laundry.

[0006] Referring to FIG. 1, illustrating a general drum-type washing machine, a detergent box 2 is installed in an upper front part of a washing machine body 1, and an inlet 4 for supply hot/cold water is installed in an upper rear part of the washing machine body. A tub 5 is installed within the washing machine body 1, and a drum 6 is installed within the tub to rotate to perform washing and dewatering. A drain pump 14 is installed along a drain hose 13 at a lower rear side of the washing machine body 1, to forcibly drain the water from the tub via the drain hose. A filter 15 is installed along a drainpipe 17, which is connected between the tub 5 and the drain pump 14 at a lower front side of the washing machine body 1 to prevent clogging of the drain pump 14. A multitude of dewatering holes 6 a are formed in the circumferential surface of the drum 6, enabling a flow of the water in the tub 5 into the drum. A plurality of lifts 6 b, formed at a predetermined interval adjacent corresponding recesses (not shown) formed in the circumferential surface of the drum 6, extend from the circumferential surface and protrude into the drum's interior.

[0007] In the above-described drum-type washing machine, washing and rinsing are performed using a head of water generated from the rotation of the drum 6. Specifically, as the drum 6 rotates, the lifts 6 b together with the adjacent recesses, periodically lift laundry and water up one side of the drum to a predetermined height and allow the laundry and water to fall down into the lower part of the drum, thereby creating a turbulent flow of the water and a series of ensuing eddy currents. Rather than falling from the predetermined height, however, a portion of the water collected in the recesses of the drum 6 runs down along a sidewall of the drum 6, which degrades washer performance, or causes uneven washing, since the washing or rinsing water fails to circulate thoroughly. Inadequate or incomplete circulation—whereby detergent is incompletely dissolved in the water, resulting in a precipitation of the detergent and a low liquor ratio—is a significant problem in washer performance.

[0008] To overcome such problems, a drum-type washing machine according to a related art employs a circulation pump as shown in FIG. 2 in which the water circulation system of a drum-type washing machine is schematically illustrated. That is, to enhance washer performance, the water circulation assembly circulates an undercurrent of the water in the tub by a pumping force of separate pump.

[0009] Referring to FIG. 2, a circulation pump 16 is separately installed between the drain pump 14 and the filter 15 and driven by a motor (not shown), and a circulation hose 18 is connected to the circulation pump to circulate the water to an upper part of the tub 5 to supply the water to the drum 6. Hence, when washing or rinsing is in progress, the undercurrent water in the tub 5 is discharged via the drainpipe 17 by the driven circulation pump 16 to circulate to the upper part of the drum 6 along the circulation hose 18. Meanwhile, the drain pump 14 is driven by another motor (not shown) to discharge the water via the drain hose 13.

[0010] Such separate motors, however, increase manufacturing costs and power consumption accordingly. Moreover, the structure of the system, whereby two motors must be driven and controlled separately, is overly complex.

SUMMARY OF THE INVENTION

[0011] Accordingly, the present invention is directed to a drum-type washing machine that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

[0012] An object of the present invention, which has been devised to solve the foregoing problem, lies in providing a drum-type washing machine, by which one motor is used to drive both the circulation and drain pumps.

[0013] It is another object of the present invention to provide a drum-type washing machine which reduces power consumption.

[0014] It is another object of the present invention to provide a drum-type washing machine which reduces manufacturing costs.

[0015] It is another object of the present invention to provide a drum-type washing machine which simplifies the structure of a water circulation system.

[0016] Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent to those having ordinary skill in the art upon examination of the following or may be learned from a practice of the invention. The objectives and other advantages of the invention will be realized and attained by the subject matter particularly pointed out in the specification and claims hereof as well as in the appended drawings.

[0017] To achieve these objects and other advantages in accordance with the present invention, as embodied and broadly described herein, there is provided a drum-type washing machine comprising a motor having a shaft, the motor enabling forward and reverse rotation of the shaft; a circulation pump, installed on the shaft of the motor, for circulating water by a rotational operation of the motor, the circulating pump moving a first fluid from a water circulation inlet to a water circulation outlet by a centrifugal force; and a drain pump, installed on the shaft of the motor, for draining water by a rotational operation of the motor, the drain pump moving a second fluid from a drain inlet to a drain outlet by a frictional force.

[0018] It is to be understood that both the foregoing explanation and the following detailed description of the present invention are exemplary and illustrative and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:

[0020]FIG. 1 is a perspective view of internal components of a general drum-type washing machine;

[0021]FIG. 2 is a schematic cross-sectional view of a drum-type washing machine according to a related art, illustrating a water circulation system using a separate circulation pump;

[0022]FIG. 3 is a schematic side view of a drum-type washing machine according to the present invention, highlighting the circulation pump and the drain pump;

[0023]FIG. 4 is a schematic side view of the circulation pump, drain pump, and motor of FIG. 3;

[0024]FIG. 5 is a cross-sectional view of the circulation pump of the drum-type washing machine of the present invention, shown as if cut along a line V-V of FIG. 4; and

[0025]FIG. 6 is a cross-sectional view of the drain pump of the drum-type washing machine of the present invention, shown as if cut along a line VI-VI of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0026] Reference will now be made in detail to the preferred embodiment of the present invention, examples of which are illustrated in the accompanying drawings. Throughout the drawings, like elements are indicated using the same or similar reference designations where possible.

[0027] Referring to FIGS. 3 and 4, illustrating a drum-type washing machine according to the present invention, a motor 40 having a single shaft installed under the tub 5, and a circulation pump 20 and a drain pump 30 are respectively installed, in succession, on the single shaft of the motor, such that the drain pump is installed next to the motor and the circulation pump is installed next to the drain pump. Thus, the circulation and drain pumps 20 and 30 are both driven by the same motor shaft.

[0028] The other end of the motor shaft, coincident with the shaft of the circulation pump 20 is provided with a circulation water inlet 22 into which water flowing from the tub 5 is sucked by the pumping action of the circulation pump. A circulation water outlet 24, via which the sucked water is discharged, is formed at one circumferential side of the circulation pump 20. Accordingly, the circulation pump 20 pumps the water flowing in the circulation water inlet 22 to the circulation water outlet 24. The water pumped to the circulation water outlet 24 ascends along a circulation passage 26 to be introduced to the tub 5 at an upper point of the front side thereof and in turn enters the drum 6 to soak the laundry therein.

[0029] A drain inlet 32 and a drain outlet 34 are formed at separated points on the circumferential side of the drain pump 30. The drain inlet 32 is a gate via which the water is sucked by pumping, and the drain outlet 34 is a gate via which the water is discharged via a drain passage pipe 36.

[0030] Referring to FIG. 5, detailing the configuration of the circulation pump 20, which is a centrifugal pump including a centrifugal impeller 21 having a spiral configuration, the direction of an inflow fluid that is sucked in (pumped) by a centrifugal force is perpendicular to that of an outflow fluid that is discharged. As the centrifugal impeller 21 rotates under the driving force of the motor 40, water is sucked into the circulation pump 20 via the circulation water inlet 22 formed on its rotational shaft and is jetted from the circulation water outlet 24.

[0031] To perform pumping, the centrifugal impeller 210 rotates clockwise as shown in FIG. 5. If the motor 40 rotates counterclockwise, there is no water flow produced, so that only air is passed through the water outlet 24.

[0032] Referring to FIG. 6, detailing the configuration of the drain pump 30, which is a frictional pump including a frictional impeller 31 having a plurality of vanes formed on its circumference, to move water in the impeller's rotational direction using a frictional force. The water sucked into the drain pump 30 is discharged via the drain outlet 34 when the motor 40 rotates counterclockwise as shown in FIG. 6.

[0033] Accordingly, the circulation and draining of water is performed according to the rotational direction of the motor 40 driving the circulation and drain pumps 20 and 30.

[0034] In detail, when the motor 40 rotates in a forward direction, i.e., clockwise, the circulation pump 20 circulates the water of the tub 5 by sucking in water from the bottom of the tub via the circulation water inlet 22 and discharging the water via the circulation water outlet 34. In doing so, the drain pump 30 pumps the fluid of the drain outlet 34 toward the drain inlet 32, whereby only air is passed through the drain pump; that is, no draining is performed.

[0035] The water proceeding to the circulation passage pipe 26 via the circulation water outlet 24 is pumped to enter the tub 5 (and, in turn, the drum 6) from an upper point of the front side of the tub, to be thus re-circulated.

[0036] Meanwhile, when the motor 40 rotates in a reverse direction, i.e., counterclockwise and opposite to the circulation direction, the circulation pump 20 serves to pump the fluid of the circulation water outlet 24 toward the circulation water inlet 22, whereby only air is passed through the circulation pump. Hence, there is no movement of the water. As the frictional impeller 31 of the drain pump 30 rotates counterclockwise, the water is moved by the frictional impeller from the drain inlet 32 toward the drain outlet 34. Hence, the water in the tub 5 passes through the drain outlet 34 to be discharged from the washing machine via the drain passage pipe 36.

[0037] By adopting the present invention to a drum-type washing machine, in which circulation and drain pumps are commonly connected to the shaft of a single motor, the number of motors is reduced, thereby reducing manufacturing costs and power consumption accordingly. Moreover, since the present invention has a configuration enabling circulation or draining by controlling the rotational direction of the single motor, thereby eliminating the need for separately driving and controlling two motors, which simplifies the structure of the system.

[0038] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover such modifications and variations, provided they come within the scope of the appended claims and their equivalents. 

What is claimed is:
 1. A drum-type washing machine comprising: a motor having a shaft, said motor enabling forward and reverse rotation of the shaft; a circulation pump, installed on the shaft of said motor, for circulating water by a rotational operation of said motor, said circulating pump moving a first fluid from a water circulation inlet to a water circulation outlet by a centrifugal force; and a drain pump, installed on the shaft of said motor, for draining water by a rotational operation of said motor, said drain pump moving a second fluid from a drain inlet to a drain outlet by a frictional force.
 2. The drum-type washing machine as claimed in claim 1, said circulation pump comprising a centrifugal impeller for moving the fluid of said circulation pump.
 3. The drum-type washing machine as claimed in claim 2, wherein the water circulation inlet is centrally disposed with respect to said circulation pump.
 4. The drum-type washing machine as claimed in claim 2, wherein the water circulation outlet is circumferentially disposed with respect to said circulation pump.
 5. The drum-type washing machine as claimed in claim 1, said drain pump comprising a frictional impeller for moving the fluid of said drain pump.
 6. The drum-type washing machine as claimed in claim 5, wherein the drain inlet is circumferentially disposed with respect to said drain pump at a first point.
 7. The drum-type washing machine as claimed in claim 5, wherein the drain outlet is circumferentially disposed with respect to said drain pump at a second point.
 8. The drum-type washing machine as claimed in claim 1, wherein said drain pump is installed adjacent said motor.
 9. The drum-type washing machine as claimed in claim 1, wherein said circulation pump sucks in and discharges water when said motor rotates in a forward direction.
 10. The drum-type washing machine as claimed in claim 1, wherein said drain pump sucks in and discharges water when said motor rotates in a reverse direction. 